Problem

The acceptance test suite has several tests with extremely broad parameterization matrices (runner × TFM × isolation combos), making them the most expensive tests by total wall-clock time. From a recent net48_x86 TRX analysis:

RunTestsFromMultipleMSTestAssemblies alone runs 140 times and consumes ~6.5 minutes of wall-clock time.

Suggestion

Review the parameterization for these high-frequency tests and determine whether the full matrix is necessary. Many of these tests likely validate framework-agnostic behavior and could run on a reduced set of runner/TFM combinations without losing meaningful coverage.

Possible approaches:

• Reduce DataSource attributes to cover only boundary TFMs (e.g. oldest + newest)
• Split into a "full matrix" category that runs only in CI, with a smaller matrix for local/PR runs
• Deduplicate overlapping test scenarios (see also Deduplicate tests #15464)